Knock-off block



Jan. 3, 1939: w LANTZ $142,611

KNOCK-OFF BLOCK Filed July 23, 1937 5 Sheets-Sheet l E s Q 3 Q g t Q 2 NQ Q Inventor E .Wfflan Z12 BEL mm,

Aiiorneus Patented Jan. 3, 1939 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to'devices of the character commonly referred toin the oil field as a pull-rod retainer or knock-off block whereby therod line may be connected with or disconnected from pumping power in asafe manner.

An object of the present invention is to provide a device of thischaracter which will be substantially fool-proof and will have manyadvantages over the types of pull-rod retainers or knock-off blocks nowgenerally resorted to.

The invention together with its objects and advantages will be bestunderstood from a study of the following description taken in connectionwith the accompanying drawings wherein:

Figure 1 is a side elevational view illustrating the application of theinvention and with the pullrod retainer or knock-off block in a workingposition.

Figure 2 is a View similar to Figure 1 and showing the pull-rod retaineror knock-off block in a lowered position, or in a position of rest.

Figure 3 is a top plan view of the device.

Figure 4 is a horizontal sectional view taken substantially on the line4-4 of Figure 2.

Figure 5 is an end elevational view of a barrel forming part of theknock-01f block, and

Figure 6 is a transverse sectional view through the barrel takensubstantially on the line 6-6 of Figure 1.

Referring to the drawings by reference numerals it will be seen that thenumeral 5 designates a knock-01f post having in the upper end thereofand at diametrically opposite sides of the post, slots 6 to accommodatea conventional rod line I. To the end that one end of the rod line maybe readily connected to a power unit said end is equipped with a stirrup9 swivelly connected thereto through the medium of a clamp 8, andadapted to engage a hook I l leading from the power unit.

The improved pull-rod retainer or knock-off block assembly comprises atransversely curved attaching plate or bracket l2 secured to theknock-off post 5 in a positive manner either by being welded, bolted, orotherwise secured to the Post.

Further the retainer or knock-01f block includes a substantially tubularmember or barrel l3 formed integrally with or otherwise securedintermediate its opposite ends to a tubular stem l4.

Links l5 at one end are pivoted to the stem [4 at opposite sides of thestem through the medium of bolts l6, and at the opposite end thereofsaid links l5 are pivoted through the medium of bolts I! to lugs l8formed integrally with and projecting from the bracket plate I Below thelugs l8 plate I2 is provided with lugs IS in which is journaled athreaded shaft 20 pro- I pivoted to the stem at opposite sides of thestem l0iv as at 25. The shank 26 of the yoke l5 has screwthreadedengagement with the stem of the member 23 and threaded on the stem 26 isa. jam nut 21 for securing stem and the stem of the member 23 at thedesired position of relative adjustment.

The head 22 of member 23 is secured at the desired adjustment on theshaft 20 through the medium of a set screw 28. Thus it will be seen thatmember 23 will rotate with the shaft 22 causing the stem l4 and barrelI3 to move vertically upwardly and downwardly, links l5 serving torestrain the movement of barrel l3 to the extent that the same will beat all times substantially parallel to the rod line 1.

At one end thereof the barrel l3 which in the top side thereof isprovided with a longitudinal slot 29 to accommodate the rod line I, isprovided with a flange 30 so shaped as to conformably engage theknock-ofi post 5 when the barrel I3 is 30 in raised position.

At the end thereof remote from the flange 30 there is welded orotherwise secured to the barrel l3 a suitably slotted re-inforcing plate3|. The

upper portion of the plate 3| at opposite sides of the slot in the platetaper and project upwardly beyond the periphery of the barrel I3 as at32 to provide guides. It is obvious that if the rod line 1 has for anyreason moved out of alinement with the slot 29 of the barrel l3, said 40wings or guides 32 will guide the rod 1 into engagement therewith.

The operation of the device is thought to be obvious. While the well ispumpingthe retainer or knock-01f block assembly is in the loweredposition shown in Figure 2. When the accumiulated fluid has been pumpedfrom the well and operation of the pump is discontinued the operatorsteps on the handle or pedal member 2| and when the pull-rod has beenpulled back by the power to the limit of its retractive movement hepresses down on the handle or pedal member 2| to swing the shaft 20about its axis, causing the barrel l3 to move upwardly and at the sametime in a direction toward the knock-off post 5,

the rod line 1 being received in the barrel through the slot 29. Thuswhen the weight of the sucker rod tends to return the pull rod, or rodline 'I the flanged end 30 of the barrel is 5 bearing against theknock-off post 5 and the plate equipped end 3| of the barrel is engagedby the clamp 8 thereby retarding return movement of the rod line 'I andretaining the sucker rod at the upward limit of its movement. The partsare then in the position shown in Figure 1, and with the barrel l3 thuspositioned between the knockoil post 5 and the clamp 8, connectionbetween the pull or line rod 1 and the power unit may be broken bydisengaging the hook I I from the stirrup 9, so that the jack end of theline'rod remains inoperative until the connection is restored.

When the pump is to be again placed in operation, the attendant engagesthe hook II with the stirrup 9, so that when the power operates toretract the-rod 1 the retaining barrel l3 automatically swingsdownwardly and oil of the line rod 1 due to the greater weight. of thebarrel in comparison to the handle or pedal 2|, and the 25 aweight ofthe sucker rod is again permitted to retract the pull rod for a pumpingstroke.

It will thus be seen that while the retainer or 'knock-off blockassembly must bemanually positioned for retaining the rod line inretracted position, shift of the knock-off barrel l3 to clear then-rod Iis automatic upon resumption of the pumping operation and with the firstpull stroke of the rod.

7 Having .thusdescribedthe invention whatis clalmed as new is:-

l. A knock-off block assembly for well-pump ing and operating equipment,and comprising a knock-off post provided to accommodate a rod line, asupporting bracket secured to said post below the rod line, a retainingbarrel adapted to be manually swung longitudinally and upwardly to ahorizontal position toreceive the rod line with one end of the barrelengaging said post and a relatively opposite end of the barrel en-45iigaging a protuberance on the rod line to hold the latter againstreciprocation, said barrel having a stem depending therefromintermediate the ends of the barrel, links pivotally connected at oneend to said stem and at a relatively opposite end 505m said bracket, alever-equipped shaft journaled on said bracket below the pivotalconnection between the links and the bracket, and an adjustable armconnection between said shaft and said stem for transmitting movement ofthe shaft to 55;saidt-barrel to raise the latter into engagement withthe rod line.

2. A knock-off block assembly for well-pumping and operating equipment,and comprising a knock-off post provided to accommodate a rod line, asupporting bracket secured to said post below the rod line, a retainingbarrel adapted to be manually swung longitudinally and upwardly to ahorizontal position to receive the rod line with one end of the barrelengaging said post and a relatively opposite end of the barrel engaginga protuberance on the rod line to hold the latter against reciprocation,said barrel having a stem depending therefrom intermediate the ends ofthe barrel, links pivotally connected at one end to said stem and at arelatively oposite end to said bracket, a lever-equipped shaft journaledon said bracket below the pivotal connection between the links and thebracket, and an adjustable .arm connection between said shaft and saidstem for transmitting movement of the shaft to said barrel to raise thelatter into engagement with the rod line, said adjustable arm connectionincluding a substantial T-shaped member having a head portion secured tosaid shaft and a threaded stem portion, and a yoke having armsstraddling said stem and pivoted to the latter at opposite sidesof thestem together with a threaded shank screw-threadedly engaged with thestem of said T-shaped member.

3. A knock-off block assembly for well-pumping and operating equipment,and comprising a knock-off post provided to accommodate a rod line, asupporting bracket secured to said post below the rod line, a retainingbarrel adapted to be manually swung longitudinally and upwardly to ahorizontal position to receive the rod line with one end of the barrelengaging said post and a relatively opposite end of the barrel engagingprotuberance on the rod line to hold the latter against reciprocation,said barrel having a stern, depending therefrom intermediate the ends ofthe barrel, links pivotally connected at one end to said stem and at arelatively opposite end to said bracket, a lever-equipped shaftjournaled on said bracket, and an adjustable arm connection between saidshaft and said stem for transmitting movement of the shaft to saidbarrel to raise the latter into engagement with the rod line, saidadjustable arm connection including a substantial T-shaped member havinga head portion secured to said shaft and a threaded stem portion, and ayoke having arms straddling said stem and pivoted to the latter atopposite sides of the stem together with a threaded shankscrew-threadedly engaged with the stem of said T-shaped member, and saidbarrel at the rod line engaging end thereof having upstandingprojections at opposite sides of the slot of the barrel for engaging therod line for guiding the barrel into engagement with said line.

WILLIAM F. LANTZ.

